ACS Nano 2015-05-26

Covalent modification of graphene and graphite using diazonium chemistry: tunable grafting and nanomanipulation.

John Greenwood, Thanh Hai Phan, Yasuhiko Fujita, Zhi Li, Oleksandr Ivasenko, Willem Vanderlinden, Hans Van Gorp, Wout Frederickx, Gang Lu, Kazukuni Tahara, Yoshito Tobe, Hiroshi Uji-I, Stijn F L Mertens, Steven De Feyter

Index: ACS Nano 9 , 5520-35, (2015)

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Abstract

We shine light on the covalent modification of graphite and graphene substrates using diazonium chemistry under ambient conditions. We report on the nature of the chemical modification of these graphitic substrates, the relation between molecular structure and film morphology, and the impact of the covalent modification on the properties of the substrates, as revealed by local microscopy and spectroscopy techniques and electrochemistry. By careful selection of the reagents and optimizing reaction conditions, a high density of covalently grafted molecules is obtained, a result that is demonstrated in an unprecedented way by scanning tunneling microscopy (STM) under ambient conditions. With nanomanipulation, i.e., nanoshaving using STM, surface structuring and functionalization at the nanoscale is achieved. This manipulation leads to the removal of the covalently anchored molecules, regenerating pristine sp(2) hybridized graphene or graphite patches, as proven by space-resolved Raman microscopy and molecular self-assembly studies.